F10-High ISO and blur
Higher ISO will give you less sharp images - because of the noise/grain that goes along with high ISOs.
Typically if you have 1/100 shutter at ISO 100, it'd be 1/200 and ISO200, 1/400 at ISO 400, etc. So higher ISOs can give fast shutter speed if there is good light.
I would highly suggest a flash if doing indoor portraits of your family unless you are trying to use natural light through a window or something.
|_F0A5334-Edit_small by Dester Wallaboo|
from Open Air Fashion Photography
|Feed me, me, me, me, me by Denjw|
from Attention-Seekers in Nature